99 Ford Ranger V6 3.0L shakes at 35-40MPH

[Haunted]

i just recently got this truck running from having it sit for almost a year.
it drive ok, but around 35-40MPH it shakes, if i go above 40 it goes away, and same with below 35.

I have changed plugs, wires, coilpack, rear wheel bearings.
im going to try the c/v joint and the rear main seal next, because from what i could see there is NO RMS on the back of the tranny.

any help is greatly appreciated.

 

[Haunted]

sorry if double posing is not allowed, but id like at least an idea so i might be able to start on it before something just falls off.

and also i have no tach so i cant tell when it shakes

 

[FirstOnRaceDayy]

A tire out of balance would cause the shaking. Try getting your tires balanced.

 

[my98nnj]

How old are the tires and were they inflated while the truck sat or did they go flat?
When tires sit for longer periods of time they tend to flat spot.

 

[Haunted]

How old are the tires and were they inflated while the truck sat or did they go flat?
When tires sit for longer periods of time they tend to flat spot.

but the wierd thing is that it only does it from 35-40 MPH

 

[Harder93]

Rotate the driveline maybe? Os the truck stock?

 

[jhighexplorer]

i used to have a 99 ranger 4x4 4.0 automatic....mine did the same exact thing but between 50 and 55 mph. it turned out to be the pressure plate on the tranny

 

[Haunted]

Rotate the driveline maybe? Os the truck stock?

the truck is stock other then the replacement parts ive put in.

i used to have a 99 ranger 4x4 4.0 automatic....mine did the same exact thing but between 50 and 55 mph. it turned out to be the pressure plate on the tranny

thats something ive never heard, ill give it ta try, thanks

 

[explorerpete]

Shaking

A tire out of balance would cause the shaking. Try getting your tires balanced.

This is the simplest one to check . Had same problem on my '95 Explorer when I had a wheel alignment done they also balanced my tires , drove on the highway after picking it up and it drove great . After a good 1/2 hour of driving about 40 mph the highway opened up , I accelerated to 50 and the truck started shaking , I went back down to 45 and it stopped , never went above 45 again till I got home . Called the shop and told them what happened they knew right away what the problem was, told me to come back and they would re-balance the tires , one of the balancing weights must have come off . Drove back to the shop they were very apologetic and it was a 10 minute wait until it was fixed !

 

[Haunted]

This is the simplest one to check . Had same problem on my '95 Explorer when I had a wheel alignment done they also balanced my tires , drove on the highway after picking it up and it drove great . After a good 1/2 hour of driving about 40 mph the highway opened up , I accelerated to 50 and the truck started shaking , I went back down to 45 and it stopped , never went above 45 again till I got home . Called the shop and told them what happened they knew right away what the problem was, told me to come back and they would re-balance the tires , one of the balancing weights must have come off . Drove back to the shop they were very apologetic and it was a 10 minute wait until it was fixed !

Okay, i got 4 new tires and balanced. Still does the same thing.

BUT the tech over there told me that it may be the rear axles are becoming worn. which i guess makes sense because i had a couch in the bed of the truck and it didnt shake/shimmy/anything.

so hopefully...

 

[RangerX]

Possibly the driveshaft has a dent or lost a weight, making it out of balance?

If weight in the bed helps, why not carry some weight back there all the time. I do, a couple sandbags. Pickups are so light in the rear.

 

[Haunted]

Possibly the driveshaft has a dent or lost a weight, making it out of balance?

If weight in the bed helps, why not carry some weight back there all the time. I do, a couple sandbags. Pickups are so light in the rear.

on the drive shaft it seems like there was a ring just past the rear main seal towards the back. could the be the problem?

 

[RangerX]

Maybe...on mine the balance weights are coin-like discs. If you have a driveline shop around, you could have them check the balance.